如何在c#中将文本块属性继承到自定义控件

Question

我有一个自定义的wpf控件.它基本上是一个文本块,能够对文本应用填充和描边.它已经被一个类继承了.问题是它没有像fontfamily这样的文本块属性.我想用textblock继承这个控件,所以它可以使用它的所有属性.自定义控制代码如下

namespace CustomXaml
{
public class OutlinedText : FrameworkElement, IAddChild
{
#region Private Fields

private Geometry _textGeometry;

#endregion

#region Private Methods

/// <summary>
/// Invoked when a dependency property has changed. Generate a new FormattedText object to display.
/// </summary>
/// <param name="d">OutlineText object whose property was updated.</param>
/// <param name="e">Event arguments for the dependency property.</param>
private static void OnOutlineTextInvalidated(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
    ((OutlinedText)d).CreateText();
}

#endregion


#region FrameworkElement Overrides

/// <summary>
/// OnRender override draws the geometry of the text and optional highlight.
/// </summary>
/// <param name="drawingContext">Drawing context of the OutlineText control.</param>
protected override void OnRender(DrawingContext drawingContext)
{
    CreateText();
    // Draw the outline based on the properties that are set.
    drawingContext.DrawGeometry(Fill, new Pen(Stroke, StrokeThickness), _textGeometry);

}

/// <summary>
/// Create the outline geometry based on the formatted text.
/// </summary>
public void CreateText()
{
    FontStyle fontStyle = FontStyles.Normal;
    FontWeight fontWeight = FontWeights.Medium;

    if (Bold == true) fontWeight = FontWeights.Bold;
    if (Italic == true) fontStyle = FontStyles.Italic;

    // Create the formatted text based on the properties set.
    FormattedText formattedText = new FormattedText(
        Text,
        CultureInfo.GetCultureInfo("en-us"),                
        FlowDirection.LeftToRight,
        new Typeface(Font, fontStyle, fontWeight, FontStretches.Normal),                
        FontSize,
        Brushes.Black // This brush does not matter since we use the geometry of the text. 
        );

    // Build the geometry object that represents the text.
    _textGeometry = formattedText.BuildGeometry(new Point(0, 0));




    //set the size of the custome control based on the size of the text
    this.MinWidth = formattedText.Width;
    this.MinHeight = formattedText.Height;

}

#endregion

#region DependencyProperties

/// <summary>
/// Specifies whether the font should display Bold font weight.
/// </summary>
public bool Bold
{
    get
    {
        return (bool)GetValue(BoldProperty);
    }

    set
    {
        SetValue(BoldProperty, value);
    }
}

/// <summary>
/// Identifies the Bold dependency property.
/// </summary>
public static readonly DependencyProperty BoldProperty = DependencyProperty.Register(
    "Bold",
    typeof(bool),
    typeof(OutlinedText),
    new FrameworkPropertyMetadata(
        false,
        FrameworkPropertyMetadataOptions.AffectsRender,
        new PropertyChangedCallback(OnOutlineTextInvalidated),
        null
        )
    );

/// <summary>
/// Specifies the brush to use for the fill of the formatted text.
/// </summary>
public Brush Fill
{
    get
    {
        return (Brush)GetValue(FillProperty);
    }

    set
    {
        SetValue(FillProperty, value);
    }
}

/// <summary>
/// Identifies the Fill dependency property.
/// </summary>
public static readonly DependencyProperty FillProperty = DependencyProperty.Register(
    "Fill",
    typeof(Brush),
    typeof(OutlinedText),
    new FrameworkPropertyMetadata(
        new SolidColorBrush(Colors.LightSteelBlue),
        FrameworkPropertyMetadataOptions.AffectsRender,
        new PropertyChangedCallback(OnOutlineTextInvalidated),
        null
        )
    );

/// <summary>
/// The font to use for the displayed formatted text.
/// </summary>
public FontFamily Font
{
    get
    {
        return (FontFamily)GetValue(FontProperty);
    }

    set
    {
        SetValue(FontProperty, value);
    }
}

/// <summary>
/// Identifies the Font dependency property.
/// </summary>
public static readonly DependencyProperty FontProperty = DependencyProperty.Register(
    "Font",
    typeof(FontFamily),
    typeof(OutlinedText),
    new FrameworkPropertyMetadata(
        new FontFamily("Arial"),
        FrameworkPropertyMetadataOptions.AffectsRender,
        new PropertyChangedCallback(OnOutlineTextInvalidated),
        null
        )
    );

/// <summary>
/// The current font size.
/// </summary>
public double FontSize
{
    get
    {
        return (double)GetValue(FontSizeProperty);
    }

    set
    {
        SetValue(FontSizeProperty, value);
    }
}

/// <summary>
/// Identifies the FontSize dependency property.
/// </summary>
public static readonly DependencyProperty FontSizeProperty = DependencyProperty.Register(
    "FontSize",
    typeof(double),
    typeof(OutlinedText),
    new FrameworkPropertyMetadata(
         (double)48.0,
         FrameworkPropertyMetadataOptions.AffectsRender,
         new PropertyChangedCallback(OnOutlineTextInvalidated),
         null
         )
    );


/// <summary>
/// Specifies whether the font should display Italic font style.
/// </summary>
public bool Italic
{
    get
    {
        return (bool)GetValue(ItalicProperty);
    }

    set
    {
        SetValue(ItalicProperty, value);
    }
}

/// <summary>
/// Identifies the Italic dependency property.
/// </summary>
public static readonly DependencyProperty ItalicProperty = DependencyProperty.Register(
    "Italic",
    typeof(bool),
    typeof(OutlinedText),
    new FrameworkPropertyMetadata(
         false,
         FrameworkPropertyMetadataOptions.AffectsRender,
         new PropertyChangedCallback(OnOutlineTextInvalidated),
         null
         )
    );

/// <summary>
/// Specifies the brush to use for the stroke and optional hightlight of the formatted text.
/// </summary>
public Brush Stroke
{
    get
    {
        return (Brush)GetValue(StrokeProperty);
    }

    set
    {
        SetValue(StrokeProperty, value);
    }
}

/// <summary>
/// Identifies the Stroke dependency property.
/// </summary>
public static readonly DependencyProperty StrokeProperty = DependencyProperty.Register(
    "Stroke",
    typeof(Brush),
    typeof(OutlinedText),
    new FrameworkPropertyMetadata(
         new SolidColorBrush(Colors.Teal),
         FrameworkPropertyMetadataOptions.AffectsRender,
         new PropertyChangedCallback(OnOutlineTextInvalidated),
         null
         )
    );

/// <summary>
///     The stroke thickness of the font.
/// </summary>
public ushort StrokeThickness
{
    get
    {
        return (ushort)GetValue(StrokeThicknessProperty);
    }

    set
    {
        SetValue(StrokeThicknessProperty, value);
    }
}

/// <summary>
/// Identifies the StrokeThickness dependency property.
/// </summary>
public static readonly DependencyProperty StrokeThicknessProperty = DependencyProperty.Register(
    "StrokeThickness",
    typeof(ushort),
    typeof(OutlinedText),
    new FrameworkPropertyMetadata(
         (ushort)0,
         FrameworkPropertyMetadataOptions.AffectsRender,
         new PropertyChangedCallback(OnOutlineTextInvalidated),
         null
         )
    );

/// <summary>
/// Specifies the text string to display.
/// </summary>
public string Text
{
    get
    {
        return (string)GetValue(TextProperty);
    }

    set
    {
        SetValue(TextProperty, value);
    }
}

/// <summary>
/// Identifies the Text dependency property.
/// </summary>
public static readonly DependencyProperty TextProperty = DependencyProperty.Register(
    "Text",
    typeof(string),
    typeof(OutlinedText),
    new FrameworkPropertyMetadata(
         "",
         FrameworkPropertyMetadataOptions.AffectsRender,
         new PropertyChangedCallback(OnOutlineTextInvalidated),
         null
         )
    );

public void AddChild(Object value)
{

}

public void AddText(string value)
{
    Text = value;
}

#endregion
}
}

Answer 1

继承自TextBlock：

public class OutlinedText : TextBlock, IAddChild